THE ASSOCIATION BETWEEN PARTICIPANT CHARACTERISTICS AND SERUM CONCENTRATIONS OF BETA-CAROTENE, RETINOL, RETINYL PALMITATE, AND ALPHA-TOCOPHEROL AMONG PARTICIPANTS IN THE CAROTENE AND RETINOL EFFICACY TRIAL (CARET) FOR PREVENTION OF LUNG-CANCER

As part of the multicenter Carotene and Retinol Efficacy Trial (CARET) lung cancer prevention study, we investigated the associations of bas eline demographic, health history, and nutritional intake information and the prerandomization serum concentrations of beta-carotene, retino l, retinyl palmitate, and alpha-tocopherol in a random subset of 1182 smokers and asbestos-exposed workers, Dietary intake was estimated via a self-administered food frequency questionnaire using the recently u pdated United States Department of Agriculture/National Cancer Institu te database, In multiple regression analyses, supplemental vitamin use was the strongest predictor of each of the four analytes, There was a statistically significant inverse relationship between smoking and be ta-carotene concentrations, Lower serum beta-carotene was associated w ith current smoking, higher daily cigarettes smoked, and more pack-yea rs, Serum beta-carotene concentrations were higher with increasing yea rs since stopping cigarette use, which suggests a biological mechanism for the lower serum concentration of beta-carotene in smokers, We fou nd weak inverse associations between alcohol intake and the serum conc entrations of both beta-carotene and retinol, As in previous reports, dietary intakes as measured by a food frequency questionnaire can only moderately predict serum concentrations of beta-carotene, retinol, re tinyl palmitate, and alpha-tocopherol.